1. Field of the Invention
The present invention relates to a novel glycerol group-containing organopolysiloxane, a cosmetic containing this, and a method for producing a glycerol group-containing organopolysiloxane.
2. Description of the Related Art
So far, methods for connecting a glycerol group to a silicone (Patent Documents 1 to 4) and compounds obtained by these methods have been disclosed. In these methods, an intended glycerol group-containing organopolysiloxane was obtained by a catalytic addition reaction of a glycerol having a double bond at its terminal ((poly)glycerin having an aliphatic unsaturated bond) or a derivative thereof with a methyl hydrogen polysiloxane.
However, in this method, a starting glycerol having a double bond at its terminal (unreacted glycerol) remains inevitably, so that purification processes such as washing and a hydrogenation reaction are absolutely imperative. It is known that, if these purification processes are not carried out, unpleasant odor is generated with passage of time. Alternatively, a reaction method wherein a hydroxy-containing silicone is reacted with a glycidol in the presence of an acid or a base catalyst is known; but in this method, there is such a problem that breakage or rearrangement of a siloxane chain by presence of an acid or a base catalyst is unavoidable. Further, special purification processes such as neutralization after the reaction and removal of a produced salt are necessary.
A technology to apply a glycerol group-containing organopolysiloxane to a cosmetic has been developed as one application example of this compound (Patent Documents 2, and 4 to 6). However, although a conventional glycerol group-containing organopolysiloxane, if blended in a cosmetic, can give a moist feeling because of its excellent water holding ability, there have been problems of stickiness and poor durability of the moist feeling.